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Micropropulsion Technologies 247

TABLE 11.4
Performance Characteristics for Laser Ablation Thruster System
430 sec
I sp
I-bit (if pulsed) 0.01 mN sec
Rep. rate (if pulsed) 100 Hz
Power 8.6 W
Thrust 635 mN
Thrust or power 74 mN/W
Impulse or prop. 4.2 N sec/g
Feed mechan. Yes
Total impulse/sys.-mass 10 Ns (450 Nsec)/750 g
Current system mass 750 g
(includes PPU, valve, tank, etc.)

FIGURE 11.12 Laser ablation thruster. (Source: Photonics Associates.)

associated with a miniaturized ion thruster design. The discharge, which acts as the
source for the ions, suffers from increased electron wall losses at greater surface-to-
volume ratios imposed by smaller discharge chambers. Consequently, maintaining
sufficient electron residence time in the chamber presents a significant challenge.
Current research at NASA JPL attempts to overcome this issue and to turn the
microion thruster into a competitive micropropulsion device.

© 2006 by Taylor & Francis Group, LLC